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Agreed. And darn hard to beat $10 bucks. And he'll get it right the first time.
Carbs chemical and ultrasonically cleaned plus completely overhauled including main jets, needles, floats and float valve seats, O-rings, seals, etc.
Also, the return to idle when the throttle is blipped is pretty slow. Would slide piston return springs help that?
Thanks for the response. And apologies to all for soliciting parts on the forum. Didn't realize that was taboo. Anyway, the diaphragms are new and butterfly plates are installed correctly. Throttle cables are by no means new but cleaned up well and are not the problem. Bowden system was a mess but that has been cleaned and re-lubed. Throttle shaft return to idle stops is brisk and complete; just takes longer than I would expect for RPMs to settle back to idle. When I ordered my carb parts from Bing Agency, I asked about slide return springs and Fay indicated they were not standard on this carb model but "could be added if necessary". I was wondering if slower response was a reason to consider doing that.Did you carefully check the diaphragms for any minute holes? Did you get the butterflies back in - facing the correct direction (assuming you pulled them out to replace the o-ring on the throttle shaft(s)).
Necessary Bing reading > http://bmwmotorcycletech.info/earlybingR75CV.htm
I'm not sure how you could rig a return spring on CV carbs, but synching the carbs should take care of it; at least it made a difference for me. But there are several possible suspects for a slow throttle return. You might want to consider replacing the throttle cables; doing a clean and lube on the handlebar perch; old grease and grime can make of a sluggish return. With regard to those throttle shaft(s) - I have found that a tiny dab of lithium grease on the shaft (where the o-ring rides) aids throttle return quite a bit; when compressed by the throttle shaft hole, the o-ring can add a lot of resistance to the shaft rotating freely.
If it looks like this, disassemble and thoroughly clean every thing up. Reassemble and lube. And don't use anywhere near this amount of lubricant.
Personally, I prefer "dry" graphite lubricants vs. "grease"; doesn't attract grit and grime. I inspect it a little more frequently, but have never experienced any problems using graphite.
Read through this > http://www.w6rec.com/duane/bmw/control/index.htm
Thanks for the response. And apologies to all for soliciting parts on the forum. Didn't realize that was taboo. Anyway, the diaphragms are new and butterfly plates are installed correctly. Throttle cables are by no means new but cleaned up well and are not the problem. Bowden system was a mess but that has been cleaned and re-lubed. Throttle shaft return to idle stops is brisk and complete; just takes longer than I would expect for RPMs to settle back to idle. When I ordered my carb parts from Bing Agency, I asked about slide return springs and Fay indicated they were not standard on this carb model but "could be added if necessary". I was wondering if slower response was a reason to consider doing that.
You are quite accurately describing the symptoms of a sticking mechanical ignition advance mechanism. .
Thanks, Paul. I will check that out.You are quite accurately describing the symptoms of a sticking mechanical ignition advance mechanism.
The tang is missing but so is the lower curved section of the right side leg. Rusted away just below the cross member. I'll pull it off and see if it can be repaired but a replacement makes more sense. They are still available new but > $200!You're going in the right direction on the carbs. Yes, the slide springs will fit on the older model carbs.
If your centerstand is in good shape other than the tang being broken off, you can fix that pretty easily. Get a piece of 1/4in. round stock from Home Depot or Lowes. Grind the area that the tang was attached to the stand (flat). Drill straight through with a 1/4in. drill. Weld both sides. Install the centerstand. With a little patience and a propane torch you can duplicate the bend going up and around the muffler. Cut the excess off, paint it and be done. Just remember that that tang is used only for dropping the stand to the ground. NOT for use when putting the bike onto the stand.
The tang is missing but so is the lower curved section of the right side leg. Rusted away just below the cross member. I'll pull it off and see if it can be repaired but a replacement makes more sense. They are still available new but > $200!